Lax oversight at the IRS increases the risk that political and religious groups could be unfairly targeted for audits, government investigators say in a report that raises concerns about an IRS division that has been under scrutiny for singling out conservative organizations.

Doris Ranzman had followed the expert advice, planning ahead in case she wound up unable to care for herself one day. But when a nursing-home bill tops $14,000 a month, the best-laid plans get tossed aside.